US2588961A - Choke control - Google Patents

Description

arch I1, 1952 H. A. EARLSON ET AL CHOKE CONTROL Filed Oct. 28, 1946 INVENTORS HAROLD A.CARLSON DONALD E.ALF'ORD ZATTORNl-QY illustrated which:

Patented Mar. 11, 1952 2,588,961 CHOKE CONTROL Harold A. Carlson, University City, and Donald E.

Alford, St. Louis, Mo., assignors to Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application October 28, 1946, Serial No. 706,244

' This invention relates to carburetors for in- 'ternal combustion engines and consists particularly in a novel choke valve control therefor.

A Reissue Patent No. 22,030, in the name of Henry Boller illustrates a manual control for a the valve spring and ultimately lock the valve closed. In the former case, the force which holds the choke closed for starting is sometimes not "enough, but the condition cannot be cured by merelystrengthening the choke spring. In the latter case, considerable skill of the operator is required in proper tensioning of thechoke spring.

It is an object of the present invention to provide a manual choke control combining the advantages of both the above devices.

A more detailed object is to provide a manual ichoke control in which the opening movement of the choke valve during the warm up period is resisted by a uniform force in all positions of the valve, while at the same time providing means to lock the valve closed without affecting the choke resisting spring. l

hese objects and other more detailed objects hereafter appearing are attained by thedevice in the accompanying drawings in Fig. l is a side view and section illustrating somewhat diagrammatically an automobile carburetor embodying the invention.

Fig. 2 is a detail section taken substantially on line 2-2 of Fig. -1.

Fig. 3 is a side view of the upper part of the carburetor in Fig. 1 but showing the choke valve closed.

- Fig. 4 is a detail, enlarged section taken on line 4-4 of Fig. 2.

Figs. 5, 6, and 7 show parts of the control mechanism disassembled.

The carburetor comprises a, downdraft mixture conduit l having an air inletportion II at its upper end, multiple Venturi tubes I2, and an outlet portion |3 flanged, as at l4, for attachment to the usual engine intake manifold (not shown). Adjacent the mixture conduit is the usual constant level bowl I in the lower portion of which v 12 Claims. (Cl. 251-163) metering rod I1.

or jet [6 controlled by a Main fuel passage I18 extends upwardly at an. angle from jet l 6 and terminates within smallest Venturi tube l2. The admission of air to the upper end of the carburetor is controlled by an unbalanced, butterfly choke valve I9 pivotally mounted on a shaft 20 journalled in is main metering orifice the walls of the air inlet portion. A butterfly throttle 2| is mounted in the outlet portion of the carburetor to control the discharge of mixture therefrom. Idling fuel is supplied through the usual idling passages 22 and 23 and ports 24 located adjacent and posterior to the edge 0 throttle valve 2| when closed.

A disk-like arm 25 is formed rigid with one extremity of choke shaft 20 and has an inwardly bent lip 26. A pair of actuating levels 21 and 28 are rotatably mounted on boss 29 which journals the adjacent end of shaft 20. Inner lever 28 has a circular opening 30 journalled on the boss. On the other hand lever 21 has an open sided recess 3| which is received in an annular groove 29a in the boss. A rivet 32 connects the free ends of these levers and carries a ball 33 for pivotal attachment to a rod 34 which extends to the drivers compartment for manual actuation of the choke valve.

A coiled spring 38 is received upon boss 29 and has one of its extremities 39 hooked over both levers 21 and 28 and its other extremity 40 hooked around inward finger '26 on disk lever 25. This spring appliestorsional force tending to maintain'levrs 2! and 28 aligned and in engagement with finger 26. A fixed stop 4| on the air inlet of the carburetor is in position to be engaged by outer lever 21 whenthe choke valve has been just moved to its closed position. Under lever 28 has acut-out right hand edge, as at 42, which causes upper lever 21 to engage the stop first. Lever 21 is provided with a flattened portion 43 along its left band edge (Fig. 6) for a purpose to be described hereafter. I

In operation, levers 21 and 28 and arm 25 on the choke shaft operate as a unit, when the operator pulls on the-choke button and rod 34, to move the choker valve to its closed position for starting. Lever 21 just engages stop 4| as the choke valve is closed. If the operator continues to pull on the rod, lever 21 rocks about stop 4| to cause its flattened edge 43 to bear against the inner surface of lip 26 with considerable force soas to lock the choke valve closed. The operator then starts the engine and immediately slightly releases the choke control rod to relieve edge 43 from its bind- .ing and locking engagement with lip 25. Thereafter, direct action of air on the unbalanced choke valve causes it to open relative to lever 21, but the resistance of spring 38 is uniform in every position of the lever as the engine becomes warm, the operator pushes in on his choke button in the usual manner and ultimately moves the choke valve to its wide open position, as shown in Fig. 1.

The invention may be modified in various respects as will occur to those skilled in the art and the exclusive use of all modifications as come. within the scope of the appended claims is contemplated.

We claim:

1. In a carburetor, an air inlet, an unbalanced choke 'valve mounted on a shaft journalled in the walls of said inlet, an operating lever yieldingly connected to said valve, an element rigidly movable with said valve, a stop limiting rotation of said lever in the valve closing direction to its valve closing position, and. means to actuate said lever to open and close said valve; said lever bein pivotable, at least in part, about said stop when in engagement with said stop for cooperating with said element to lock said valve closed.

2.. In a carburetor, a mixture conduit, an unbalanced choke valve mounted therein, a choke actuating lever having a pivotal mounting, means 'yieldingly resisting opening of said valve relative to saidv lever, a stop limiting the rotation b 'of said lever about said mounting in the valve closing direction to the position for closing said valve, an element movable with said valve .and means to pivot said lever about said stop when said valve. is closed so as to cooperate with "said element to apply resistance. to opening of said valve in addition to said yielding resistance means;

3., In a carburetor, an air inlet, a choke valve,

means mounting said valve in said inlet in a manner permitting opening of said valve by direet action of air pressure thereon, actuating leverage for said valve and a pair of pivots for 5. Carburetor structure as described in claim 3 in: which said leverage has two parts, one part being swivelable about one of said pivots to. open and close said choke valve and the other part being swivelable about the other pivot to bear against said element and" thereby lock said valve in closed position. Y

6. Carburetor structure as described in claim 3 further including a spring normally stressed between said valve and said leverage and apply- 7 ing uniform force resisting opening of said valve in all'positions' of said leverage.

7. Carburetor structure as described in claim 3 in which said leverage has two parts, both of said parts being swivelable as a unit about one of said pivots to open and close said choke valve andone of said parts being swivelable about the other pivot when said valve is closed so as to bind against said element and thereby lock said valve.

8.. In a carburetor, an air inlet, an unbalanced choke valve mounted therein on a shaft, an operating lever pivotally mounted about said shaft, an arm rigid with said shaft and having a part extending across the edge of said lever, a spring between said lever and arm and normally maintaining the same in engagement while permitting opening movement of said choke valve relative to said lever, a stop limiting choke closing movement of said lever to its choke closing position, and means for tilting said lever about said stop to cause the same to bind against said arm and thereby lock the choke valve in closed position.

9'. In a carburetor, an air inlet, a choke valve mounted-therein on a shaft, an operating lever loosely pivoted about said shaft, a spring normally maintaining said choke valve and lever in predetermined relative positions and yieldable under the suction applied to said valve to resist opening of said valve relative to said lever with uniform force in all lever positions, a stop limiting rotation of said lever in the valve closing direction to justclose; said, valve, and means for tilting said lever about said step in a manner-to bind against said shaft. and additionally resistflopeniing ofv said choke valve without affecting the tension of said spring a "10.; In a carburetor; an air inlet, an unbalanced butterfly choke valve mounted in said inlet on a shaft, a choke actuating lever having one end loosely pivoted about said shaft and linearly shiitable relative to said shaft, an arm rigidwith said shaft and having a portion extendin :athwart the edge of said lever, a spring stressed between said lever and arm and normally maintaining the same in abutting relation while yieldinglyv resisting opening of said choke valve relative'to said lever, a'stop limiting rotation of said lever in the. valve closing direction to the position to just close said valve, means to rotate said lever toqopen and close said valve, and: meansto rock said lever about said step after said valve is closed to shift the pivoted end thereof into binding engagement with said arm, for locking said choke valve closed; 7

ll. Carburetor structure as described in claim 10 further including a stabilizing lever lying in juxtapositionto said previously-mentioned shiftable lever and movable therewith asa unit except during the shifting of said first lever to lock the valve.. V Y

1.2. Ina carburetor, an air inlet, an unbalanced choke valve mounted in said inlet, an operating lever resiliently connected to said valve, meansto actuate said lever to open and close saidvalve, 'a stop limiting the rotation of said lever in the valve closing direction to its valve closing position, and an element rigidly movable. with. said valve; said lever, after it is in engagement with said stop, being pivotable, at least in part, about said stop to cause it to bind against said element and thereby "resist opening of said valved HAROLD A. CARLSON. DONALD E. ALFORD;

REFERENCES CITED The following references are of record in the file of this patent: V 1

UNITED STATES PATEhlTS- Number Name Date 1,966,2-01 Firth July 10, I934 l,986',574 Heitger Jan. 1,1935 2,017,890 .Bracke 'Oct. 22, 1935 2,065,167 Wirth Dec. 22-, I936 2,322,109 Binberg -s June I5, 1943

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